Re: [PATCH v3 12/13] mm/debug_vm_pgtable/hugetlb: Disable hugetlb test on ppc64
From: Anshuman Khandual <hidden>
Date: 2020-09-01 04:03:44
Also in:
linux-arch, linux-mm, linux-s390, linuxppc-dev
On 08/27/2020 01:34 PM, Aneesh Kumar K.V wrote:
The seems to be missing quite a lot of details w.r.t allocating the correct pgtable_t page (huge_pte_alloc()), holding the right lock (huge_pte_lock()) etc. The vma used is also not a hugetlb VMA. ppc64 do have runtime checks within CONFIG_DEBUG_VM for most of these. Hence disable the test on ppc64.
Would really like this to get resolved in an uniform and better way instead, i.e a modified hugetlb_advanced_tests() which works on all platforms including ppc64. In absence of a modified version, I do realize the situation here, where DEBUG_VM_PGTABLE test either runs on ppc64 or just completely remove hugetlb_advanced_tests() from other platforms as well.
quoted hunk ↗ jump to hunk
Signed-off-by: Aneesh Kumar K.V <redacted> --- mm/debug_vm_pgtable.c | 4 ++++ 1 file changed, 4 insertions(+)diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index a188b6e4e37e..21329c7d672f 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c@@ -813,6 +813,7 @@ static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) #endif /* CONFIG_ARCH_WANT_GENERAL_HUGETLB */ } +#ifndef CONFIG_PPC_BOOK3S_64 static void __init hugetlb_advanced_tests(struct mm_struct *mm, struct vm_area_struct *vma, pte_t *ptep, unsigned long pfn,@@ -855,6 +856,7 @@ static void __init hugetlb_advanced_tests(struct mm_struct *mm, pte = huge_ptep_get(ptep); WARN_ON(!(huge_pte_write(pte) && huge_pte_dirty(pte))); } +#endif
In the worst case if we could not get a new hugetlb_advanced_tests() test that works on all platforms, this might be the last fallback option. In which case, it will require a proper comment section with a "FIXME: ", explaining the current situation (and that #ifdef is temporary in nature) and a hugetlb_advanced_tests() stub when CONFIG_PPC_BOOK3S_64 is enabled.
quoted hunk ↗ jump to hunk
#else /* !CONFIG_HUGETLB_PAGE */ static void __init hugetlb_basic_tests(unsigned long pfn, pgprot_t prot) { } static void __init hugetlb_advanced_tests(struct mm_struct *mm,@@ -1065,7 +1067,9 @@ static int __init debug_vm_pgtable(void) pud_populate_tests(mm, pudp, saved_pmdp); spin_unlock(ptl); +#ifndef CONFIG_PPC_BOOK3S_64 hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); +#endif
#ifdef will not be required here as there would be a stub definition for hugetlb_advanced_tests() when CONFIG_PPC_BOOK3S_64 is enabled.
spin_lock(&mm->page_table_lock); p4d_clear_tests(mm, p4dp);
But again, we should really try and avoid taking this path. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel